Online collaborative computing sessions, such as interactive conferences (e.g., conferences/meetings), may be supported by a network of servers and client computers. In particular, one feature available to online meetings or data conferencing systems is to allow computer users at different locations to communicate via a computer network and share applications stored and/or executed on one of the users computers, such as through a software program that enables the users to share applications (e.g., sharing a presenter's application with one or more attendees/viewers).
A conventional technique for sharing applications during a data conference is to share a predefined area of the presenter's computer screen with an attendee (e.g., “desktop sharing”). Using this technique, the presenter's computer captures an image within a predefined portion of the presenter's computer screen/display (e.g., the entire screen or a portion of the screen). The captured image within the predefined portion of the presenter's computer screen is then transmitted to the attendee's computer for viewing. Thus, replicas of any windows that are displayed within the predefined portion of the presenter's computer screen are displayed on the attendee's computer screen. A refinement to this conventional technique allows the presenter to selectively share an application with the attendee (e.g., “application sharing”). In particular, only those windows of a shared application may be seen by the attendees. Thus, windows of non-shared applications placed within the predefined portion of the presenter's computer screen may be blocked from the attendees.